How to respond to "half offer"?

[gls2814]

So I applied for a doctorate at a school. They replied that although they could not admit me for the PhD program, they would like to offer me admission to the Masters program and recommend to the GSAS that I be granted a merit-based scholarship. 

The professor said that GSAS will be sending me the details soon. 

I am seriously considering the MA at this school, but I also want to know how my other 8 applications play out. I've had interviews at schools I haven't heard from yet and which haven't sent out results. 

The email with the MA offer didn't have details about money or anything and he did say that GSAS would follow up soon. 

I truly have no clue how to proceed or respond to this professor/offer. He also CCed my POIs (the one who wrote me is not a POI of mine). 

How do I respond to keep this opportunity open while letting them know I'd like to wait for other decisions?

[hopeful2020PhD]

Do they actually need a follow up now? If so, simply state that you would potentially be interested, and ask for details about the scholarship.